In the first of four pieces by photographers talking about their famous pictures, amateur Charles Porter describes how he captured the defining image of the Oklahoma City bombing in April 1995. His pictures won a Pulitzer Prize.

I am talking about two photographs that I took on 19 April 1995 from the Oklahoma City bombing.

One being of a policeman handing an infant to a fireman and the other of a fireman gently cradling this lifeless infant.

I have these images in front of me here, looking at them now, and there are things that strike me.

One is that the fireman has taken the time to remove his gloves before receiving this infant from the policeman.

Anyone who knows anything about firefighters know that their gloves are very rough and abrasive and to remove these is like saying I want to make sure that I am as gentle and as compassionate as I can be with this infant that I don't know is dead or alive.

And the second image is of this fireman just cradling this infant with the utmost compassion and caring.

He is looking down at her with this longing, almost to say with his eyes: "It's going to be OK, if there's anything I can do I want to try to help you."

He doesn't know that she has already passed away.

Spring morning

And these images are in such contrast with the day.

It was such a beautiful, crisp, bright spring morning. And at 0902 it was just amazing.

Our building shook and I looked out the window and saw this huge brown cloud of dust and debris and papers just flying in the air, and as I ran across towards the debris cloud, I turned this corner at the building and the street was covered with glass.

There were people on the street that were injured and bleeding, and there was a gentleman that was walking towards me who had taken his dress shirt off from the office building that he was in and had it to his head, and blood was dripping from that.

I just took my camera out and instinctively started taking pictures.

I ran to the front of the building and took some images of that, and as I ran back down the side, I noticed this ambulance where these firefighters were working on these people that were wounded and mortally wounded, and I noticed something out of the corner of my eye that was running across my field of vision.

First frame: The police officer hands the baby to the firefighter

I didn't know what it was, but I trained my camera on it and it was this police officer.

And as this policeman handed this infant to the fireman, I took one frame and then as the fireman is cradling this infant I took the second frame and that is exactly how these images came to be on 19 April 1995.

After I left I got my film developed and called a friend who was the head of photography at a local university.

I called him, and he said: "If you have images that have just happened, you need to go to somebody that wants to see them, like the Associated Press or somebody like that."

I looked the address up in the phone book, I got in my car. I drove over there. I knocked on the door and I went in and said: "Hi, I've got some images of what you're seeing on TV and wanted to know if you would like to look at them?"

Speechless

Wendel Hudson, who was the AP photo editor at Oklahoma City at the time, picked them out immediately and said: "We'd like to use these." And I thought: "Wow!"

Chills go over me just to think about the magnitude and the enormity of where that picture went

It went out on the AP wire, and not knowing exactly what the AP wire is, I go home and I honestly went home and told my wife: "You know what, I just took some images and they might be in the Daily Oklahoma tomorrow."

I go home about 1300. About 1320 I get this phone call from this lady and she says: "Hi, I am so-and-so from the London Times and I want to know if you are Charles Porter."

I said: "Yes I am, but how do you know who I am?"

She said: "Well I just received your image over the AP wire..."

And she proceeded to explain to me what the Associated Press wire was.

I said that I didn't know how to respond and she said, "Well sir, can I ask you one question?" And this is where it hit home: "Could I get your reaction and response to what your feelings are going to be, knowing that your image is going to be over every newspaper and every magazine in the entire world tomorrow?"

I was silent and speechless, and chills go over me just to think about the magnitude and the enormity of where that picture went and the impact that picture had at that time.

It was beyond my scope of comprehension and understanding, way beyond.

Charles Porter gave this account to the BBC World Service programme, the World Today.